A day intended to be one of celebration and jubilance for Washington’s gay community took on a more somber tone Sunday as participants reacted to news that the alleged gunman who killed 50 people at an Orlando nightclub may have targeted them because of their sexual orientation.

Amid preparations for Sunday’s Capital Pride Festival, which was expected to attract tens of thousands of people, some said the celebration has now become a symbol that while the LGBT community has much to celebrate for the progress it has achieved, there is still work to do. There is still hatred. And there is still reason for fear.

In Southern California, a heavily armed man was arrested early Sunday and told police he was in the area for West Hollywood’s huge gay pride parade, Los Angeles Mayor Eric Garcetti said.

Garcetti announced the arrest Sunday while attending the LA Pride kickoff.

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A law-enforcement source with knowledge of the investigation told The Associated Press that guns and explosive materials were found in the suspect’s vehicle.

And Tony Awards organizers are dedicating Sunday’s ceremony to the dead as Broadway performers rush to embrace the LGBT community.

“Our hearts are heavy for the unimaginable tragedy that happened last night in Orlando. Our thoughts are with the families and friends of those affected,” the Tony Awards said in a statement Sunday. “The Tony Awards dedicate tonight’s ceremony to them.”

Organizers didn’t say how the evening’s Tony broadcast would be affected, but “Hamilton” – the musical about Founding Father Alexander Hamilton that is expected to win big – will drop its use of muskets in its performance, according to a show’s spokesman.

Performers who have strong ties to the gay community like Donna Murphy and Audra McDonald took to Twitter to express their outrage over the attack. Lin-Manuel Miranda, the star and creator of “Hamilton” tweeted a rainbow-colored heart with “Orlando” written beneath it.

“It’s a sad day for all of us and a powerful reminder that there’s still a lot of hatred in the world,” said David Mariner, executive director of the DC Center for the LGBT Community. “Much work remains all around the world. And much work remains right here in the District of Columbia.”

Authorities say a gunman opened fire inside a crowded gay nightclub in Orlando early Sunday, killing 50 people and injuring 53 others, in the deadliest mass shooting in U.S. history.

Police said that after the first round of gunshots at 2 a.m., the alleged gunman, Omar Mateen, 29, took hostages for about three hours until officers went inside to rescue them and killed the gunman in a shootout.

D.C. festival organizers said events here would go on as planned, but with increased security.

D.C. Mayor Muriel Bowser said in a statement she was briefed by D.C. Police Chief Cathy Lanier about additional security measures being taken. Police said in a tweet that revelers could expect additional police presence at the festival, which began at noon on Pennsylvania Avenue.

“This morning, our hearts are heavy after hearing about the tragedy in Orlando. Just yesterday, we held the annual Capital Pride Parade, a celebration of the rich diversity and contributions of the LGBTQ community in the District of Columbia,” Bowser said. “Today as always, we will not be deterred by hate as we gather to celebrate love.”

At the festival, the shooting was marked with a brief moment of silence before the Gay Men’s Chorus’ performed “The Star Spangled Banner.” Hundreds of participants stood, rainbow flags between their fingers, holding their hands over their hearts and clutching their loved ones.

“By now we are all aware of the senseless killings at the Pulse Nightclub in Orlando, Florida,” said Bernie Delea, board president of Capital Pride. “We deplore this senseless act of wanton violence against members of our community. And I would like to now ask is for a moment of silence in remembrance of those who died.”

“My home state yesterday and earlier today had a terrible tragedy and we would like to dedicate our performance today to the people of Orlando,” he said.

James Dallas Dunn, 28, of Arlington, Virginia, said he and his boyfriend had a conversation early Sunday morning about whether they should even attend Capital Pride, given the fear prompted by the shooting.

“We talked about it. Should we stay home?” he said. In the end, he said, it was important not to let the attack deter them.

Still, Dunn, who served eight years in the U.S. Marines, said his senses were heightened Sunday afternoon.

From a generational standpoint, the shooting was a reminder of the ongoing struggle for LGBT acceptance.

“Our generation of the LGBT community has never not seen the progression of acceptance,” he said. “Events like this make us remember how little we’ve really progressed.”

Kris Archer, 33, of Greenbelt, Maryland, said the Pride celebration presented an odd dichotomy given the shooting’s occurrence just hours earlier.

“You want to be happy, but you’re sad about what happening down there,” she said. “You don’t have to look, you don’t have to agree with us, but you don’t have to kill us.”

Across the city, members of the LGBT community wondered whether nightclubs here need more security in light of the shooting. JR’s, a popular bar, has already instituted a no-bag policy.

“This tragedy in Orlando needs to be a wake up call to all of us,” the bar said in a statement posted on Facebook on Sunday. “If you are a bar patron, if you see something, say something. ... Today we again will not be allowing bags (into) JR’s, and we won’t in the future.”

Early reports indicated that Mateen, who is Muslim, might be affiliated with radical extremists. A U.S. official said that Department of Homeland Security reports being circulated to government authorities are “referring to local law enforcement reports saying the shooter pledged loyalty to ISIS and was heard praying in another language in the nightclub.”

Authorities have not made any official connection and local Muslim leaders joined those in Florida in condemning Mateen’s actions.

The Muslim community in the Washington region, said Ibrahim Hooper, spokesman for the Council on American-Islamic Relations, has reacted with “horror.”

“They’re horrified just like everyone else,” Hooper said. He declined to comment further, saying now is a time of “healing from this horrific and heinous attack.”

In Dupont Circle, where the Capital Pride parade thundered through the streets Saturday, people struggled to simultaneously celebrate the gay community’s triumphs - like last year’s legalization of gay marriage - while mourning a tragedy that has rocked it. Some suggested the growing role that gays play in the national conversation and culture has, to some degree, fomented a violent backlash.

“Gay visibility is going to inevitably make life a little worse for gay people before it gets better,” said Matthew Viator, 31, as he walked down P Street with his mother.”You are going to stir a hornet’s nest of people who really, really wish you don’t exist. And they are going to strike.”

Others said they see Washington’s clubs in what happened in Orlando. “That could have been any gay bar, any gay club in any community,” said Brock Thompson, an emcee at Saturday’s pride parade, walking with friends. “When you have progress like we had, there will be hiccups.”

Rather than deter Sunday’s celebrations, Orlando’s attack should in fact embolden it, others said. “Pride has always been about celebration,” Mariner said. “But it’s also about community. And I can’t imagine a day when our community needs to be together more than this day.”